Concordia University

About: Concordia University is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Control theory & Population. The organization has 13565 authors who have published 31084 publications receiving 783525 citations. The organization is also known as: Sir George Williams University & Loyola College, Montreal.

Stress reinstates heroin-seeking in drug-free animals: An effect mimicking heroin, not withdrawal

Abstract: Exposure to 10 min of footshock stress (1 mA; 0.5 s on, with a mean off period of 40 s) reinstated heroin-seeking behavior in heroin-experienced, drug-free rats after many sessions of extinction and up to 6 weeks after last exposure to heroin. In reinstating the behavior, the footshock mimicked the effect of a non-contingent priming infusion of heroin (50 µg/kg). By contrast, the aversive state of acute opioid withdrawal induced by injection of the opioid receptor antagonist naltrexone (5 mg/kg, SC), following an acute injection of morphine (10 mg/kg, SC), had no effect on heroin-seeking behavior. In a second experiment it was shown in drug naive animals that these parameters of footshock increased dopamine overflow in the nucleus accumbens, a terminal region of the mesolimbic dopamine system implicated in the reinforcing effects of drugs. Similarly, dopamine overflow was increased by an injection of 10 mg/kg morphine, SC, an effect that was reversed by an injection of 5 mg/kg naltrexone given 40 min after to induce the withdrawal condition. A possible interpretation of the present results is that stressors can reinstate drug-taking behavior by activating neural systems in common with those activated by heroin.

A cognitive gap between arithmetic and algebra

Abstract: Serious attempts are being made to improve the students' preparation for algebra. However, without a clear-cut demarcation between arithmetic and algebra, most of these undertakings merely provide either an earlier introduction of the topic or simply spread it out over a longer period of instruction. The present study investigates the upper limits of the students' informal processes in the solution of first degree equations in one unknown prior to any instruction. The results indicate the existence of acognitive gap between arithmetic and algebra, a cognitive gap that can be characterized asthe students' inability to operate spontaneously with or on the unknown. Furthermore, the study reveals other difficulties of a pre-algebraic nature such as a tendency to detach a numeral from the preceding minus sign in the grouping of numerical terms and problems in the acceptance of the equal symbol to denote a decomposition into a difference as in 23=37−n which leads some students to read such equations from right to left.

Corporate Environmental Disclosure: Contrasting Management's Perceptions with Reality

Abstract: This paper's purpose is to assess how management's perceptions regarding certain aspects of environmental reporting relate to the firm's actual reporting strategy. Toward that end, we propose a model where a firm's environmental disclosure is conditional upon executive assessments of corporate concerns. The study relies on a survey that was sent to environmental management executives from European and North American multinational firms enquiring about the determinants of corporate environmental disclosure. Responses from these executives were then contrasted with their firms' actual environmental reporting practices, which was measured using a comprehensive multi-criteria grid. Results show that there is a relationship between environmental managers' attitudes toward various stakeholder groups and how those managers respond to the stakeholders via the decision to disclose and the actual disclosures made. Our model provides a perspective as to how a firm responds to the numerous stakeholders to whom it must be accountable. This accountability in turn relates to how the company communicates its actions to society in order to achieve or maintain its social legitimacy.

Self-regulation processes and health: The importance of optimism and goal adjustment

Abstract: This article discusses how self-regulatory models can be used to understand people's response to health threats. The article begins with a general discussion of the principles and assumptions of self-regulatory models of behavior. Two distinct lines of research are then presented addressing two important processes of adaptive self-regulation. First, we provide a brief overview of the literature on optimism and adjustment to chronic disease and other health outcomes. Second, we present an overview of the process of disengagement from unattainable goals, focusing on recent research. We close by making recommendations for future research.